Thermal management is critical in every aspect of the microelectronics space, such as integrated circuits (IC), light-emitting diode (LED), power electronics, displays and photovoltaics. The performance of p-n junctions (the basis of these devices) is directly affected by operating temperature. Lowering the operating temperature of these devices increases lifetime and improves performance, as compared to operation at higher temperatures.
In solid state lighting business, there is strong need to improve heat management. Proper dissipation of heat in LED devices is critical to their reliable long-term operation. Failure to adequately manage the heat can have an undesirable impact on the performance of LEDs. Prolonged exposure to excessive operating temperatures can lead to irreversible damage to the semiconductor components within the LED die, resulting in lowered light outputs, changes to the color rendering index, and significantly reduced LED lifetimes. Therefore, a material with higher heat conductive property is desired for heat management of LED devices.
A heat sink in an electronic system is a passive component that cools a device by dissipating heat into the surrounding air. Heat sinks are used to cool electronic components or semiconductor components such as high-power semiconductor devices, and optoelectronic devices such as higher-power lasers and light emitting diodes (LEDs). Traditional heat sink uses aluminum fins and several copper heat pipes for cooling of high-heat-dissipation processors. A heat sink is designed to increase the surface area in contact with the cooling medium surrounding it, such as the air. However, the metals are heavy and difficult to process a complex form. Therefore, it has been required to develop a material with higher thermal conductive as well as less weight and lower processing cost as alternative to metal.
Although polymer materials are light and easy to processing, those low thermal conductive property is a barrier of application to a heat sink. However, it is known polymers with ordered structure have higher thermal conductivity. Therefore, crystalline polymers or liquid crystalline polymers are studied as an alternative of metal used for a heat sink.
Some liquid crystalline thermosetting resins have been studied materials which have high heat conductive properties, see e.g. JP2010163540, U.S. Pat. No. 5,811,504 and WO2011040416. However, those resins generally have insufficient thermal conductivity or are difficult to process or mold as an article.
Another solution to increase the thermal conductivity of a thermosetting resin is adding high amounts of thermal conductive materials within a thermosetting resin. Since ceramics such as boron nitride show high thermal conductivity, ceramic filler can be added within a thermosetting resin to increase thermal conductivity of a thermosetting resin, see e.g. US5900447. However, quite high amount of filler is needed for thermal conductive resin, it causes a difficulty for process because the high pressure is needed to mold such resin.
Accordingly, a cured thermoset with high thermal conductivity and easy processability suitable for a thermal management element of electronic devices is desired.